Iridoids from Bellardia trixago (L.) All.

The phytochemical study of the polar fraction of Bellardia trixago (L.) All. led to the isolation of eight iridoid glucosides. Five of these glucosides (aucubin (1), bartsioside (2), melampyroside (3), mussaenoside (4) and gardoside methyl ester (5)) were confirmed as they were previously isolated from this plant, and the remaining three known compounds (mussaenosidic acid (6), geniposidic acid (7) and 8-epiloganin (8)) were isolated here for the first time. Of particular interest were the presence of 7 and 8 due to two reasons: the first one because it is not accompanied with geniposide, the corresponding methyl ester, as in the case of 4 and 6, and the second one because it is the parent compound of iridoids characteristic of Orobanchaceae family. Also an alditol, D-mannitol (9), was recognised for the first time from this species.